This device relates to the identification of roof bolts or stabilizers that are used in the mining industry or tunneling underground, and more particularly to the marking and identification of roof bolts and stabilizers that can be more easily identified pre and post installation.
Many different types of devices and methods are used to secure the roofs in mining or tunneling operations. Generally these devices consist of cables, rods, screws or tube like stabilizers that are inserted through a hole in a plate of some kind and into holes drilled in the roofs or walls of the tunnels. These devices can penetrate great distances into the ceilings or walls dependent upon the consistency or materials in the roof or walls and the stabilization plan. The plates generally sit flush against the ceiling (for example) in the tunnels and the bolts or stabilizers are secured in the drilled holes in the ceiling. The bolts or stabilizers are in tension and the plates help retain the roof material in position once the tunnel material is removed and this helps prevent ceiling failures or collapse. Stabilizers once installed, can then have a grout or an adhesive inserted into the interior of the tube of the stabilizer that aids in securing the stabilizer in the roof or ceiling.
One method of aiding in the securing of the ceilings or walls of mining tunnels is to first drill a hole and check the material removed. This drilling and other methods tell the operator how deep the hole should be drilled and how long the stabilizer or roof bolt should be. Once the hole depth has been determined, the appropriate type of device of the appropriate length and properties can be inserted into the hole and secured. Securing can be done by a number of different methods known in the art. Some roof stabilizers use a grout, others use an epoxy material and still others use neither but are held in place via friction from the outer surface of the stabilizer in the hole drilled in the roof material.
Some stabilizers have a roof bolt inserted along with the grout or epoxy into the stabilizers to aid in retaining the stabilizers in the hole in the rock. The roof bolts generally have a head of various designs attached to an extension that varies in length depending upon the roof plan and length of the stabilizer. The extensions can be cable, solid rod, threaded rods or various other designs known in the art. These bolts suffer from the same pre and post installation identification problems as the stabilizers.
All stabilizers have indicia to indicate various properties of the stabilizer, for example only and in no way meant to be a limitation, length, material, strength, date of manufacture, lot number, machine manufactured on, plant or manufacturers facility and others. The problem with much of the background art is that this indicia is located on the interior surface of the stabilizer. This can be impossible to see if the stabilizer has a grout, epoxy material and/or a roof bolt inserted into the stabilizer. Any material or device inserted into the stabilizer can cause difficulty in reading the indicia if the stabilizer is many feet away from the inspector or installer. The indicia may become difficult to read from corrosion of the stabilizer itself or the indicia may wear or flake off.
It is important to enable one to visually verify that the proper length stabilizers have been inserted into the proper depth hole to make sure that the roof plan has been followed. The Applicant's device allows the stabilizers to be visually verified before installation and visually verified at a later date for inspection, even if the roofing plan has been lost or was not fully completed. The Applicant's device is more clearly visible to the installers and inspectors and is much less likely to become corroded to a point that the indicia is not visible. Inspection can thus be done at a much later date even in low light conditions.
Several other methods such as paint or locating the ring at a particular angle relative to a slot in the stabilizer have been found to somewhat enable visual inspection, but have been unsuccessful for one reason or another and none have been successfully accepted by many in the tunneling or mining industry.
For the foregoing reasons, there is a need for a stabilizer or roof bolt that allows the relative simple visual inspection of the stabilizer or roof bolt to verify the length and other properties of the stabilizer or roof bolt both before and after installation.